Internal combustion engines have revolutionized the world that we live in. In general, internal combustion engines use combustion within the engine to generate useful mechanical energy. For example, fuel and an oxidizer may be combusted within a cylinder to force a piston down and turn a crank shaft. The turning crank shaft can then be used to do work. Internal combustion engines are used in a variety of applications. For example, internal combustion engines are used as a power source for automobiles, motorcycles, locomotives, ships, airplanes, electrical power generators, snowmobiles, lawnmowers, string trimmers, chain saws, jet skis, mopeds, and go karts, just to name a few.
Recently, there has been interest in converting internal combustion engines into compressed air engines. That is, using compressed air rather than combustion to generate useful mechanical energy. However, there are many challenges to converting an internal combustion engine into a compressed air engine.